Spark plug



Patented Feb. s, 1927.

STATES PATENT OFFICE.

, JOHN M. BRINGMAN, OFBUTTE, MONTANA.

SPARK PLUG.

Application ined November 20, 19'25. sei-iai No. 70,340.

Thev present invention. relates to spark yplugs, particularly well vdesigned to facili- ,'tate'the priming of an engine cylinder in y connectionwith which the plug is used, and 1. 'is v an improvement Yon United rStates Patent `#'1,333,897, granted to me on March 16, 1920. y Y

The primary object of the invention is to y provide an'improved priming spark plug` of extremely simple construction and which plugjwill prevent leakage of gas outwardly .therethrough during the operation of the engine.

A furtlierobject of the invention resides '1in..the'provision'-of a spark plug yincluding the'usualporcelain insulator or core through vwhich the central electrode'of the plug extends, and which central electrode is shift- 'i v fable' longitudinally 'through the porcelain. in a manner forpv'ermitting of a volatile fuel placed in the head of the plug to flow about the firing point ofthe electrode.

i Other objects and advantages of the inventionwill be'apparent during the course lof'the'gfollowing detailed description, taken in' connection Ywith the .accompanying draw- .;ing, forming apart offthis specification, and

inL which drawing-v Figurek 1 is a side elevation of the im l provedspark plug constructed in accordance with my invention.

v *.Figure 2 a central vlongitudinal section through jthefplug on kline 2-2 of Figure 1, and"1 showingthel'inovable elements of the plug'in a posit-ion for preventing lealage of gas outwardly through the plug during operation oftheengine.v

-Figure. 3' is a central longitudinal section throughj the plug andfshowing the same in an' openposi'tion for permitting of a volatile priming fuel being passed through the plug for spreadingover the firing point of the Ui. i

central electrode. Y -Figur'e t is a cross section through the vrplug online L.le--Ll of Figure 1; and

. Fig'u-re 5 is-an enlarged fragmentary secn tional view of the upper portion or end of theplug.

@Referr'n'g to the drawingin detail, and Vwherein similar reference characters ldesig- .nate vcorresponding parts throughout the `several views,"1 indicates the metal shell of the's'p'ark .plug in which porcelain or insulatv ing core2 is secured asby the usual type of 4packing nut 3.

The Vcore 2 is provided with al centrally disposed bore d, kthe lower vend of'which opens out into a pocketor recess 5 opening at the lower end of the porcelain and forming a shoulder 6.

Fitting Awithin the bore et is a metal tube or sleeve 7 having a screw threaded'upper portion projecting past the top of the porcelain and having formed adjacent its lower end an annular flange S' below which a valve seat 9 extend s. rlhiis it will be seen that the shoulder 6 provides an abutment for the annular Hange 8 of the tube 7. Threaded upon the upper end of the tube 7 is a terminal binding nut 1() `which when turned into 'section and which semi-circular stem portion is of greater lengthlthan the length of the tube 7. Formed on the electrode and spaced below the lower rendof the stem portion 12, is a valve 13 having a iiat upper face for seating engagement withthe valve'seat 9 when the electrode is ina raised or closed position; YExtending from the lower side of the valve 13, and which valve is of less diameter than the inner diameter of the recess 5, is a tiring point or portion 14 which l is adapted to cxtendinto sparking relation with the outer electrode 15. A head 16 is formed at the upper end of the stem portion 12, and which head is of a size equal to the inner diameter of the tube 7 for permitting of the electrode being slid through the tube in the assembling of thespark plug.

A priming cup or cap 17 having ana'xiallfy disposed threaded lsleeve 18 for threaded engagement with the upper threaded end of theVY tube 7 is/secured to the central electrode 25 as by a pin 19`extending through' the electrode 25 at 'a point immediately below the head16. rllhus it will be seen that upon rotation of the cap 17, that the electrode will be moved longitudinally within the tube 7 for seating and unseating of the valve 13. It is preferred that the cap 17 be formed of a suitable insulating material such as fiber or the like, so as to permit of the saine being rotated during operation of the engine with which the plug is associated when desiring to determine if all of the plugs are functioning properly.

The pin 19 aside from forming a connection between the cap 17 and the central electrode, acts when the .cap is rotated in' one direction for seating the valve upon Athe valve seat 9 and closing the'passageway 20 through the tube 7,and upon rotation in the opposite direction engages with the upper end of the tube for limiting the inward movement of the elec-trode 25.

It may be here stated that the object in having the stem portion 12 of not less than semi-circular shape in cross section, is to prohibit lateral shifting of the stem within the tube 7, and which lateral shifting would prevent the valve centering portion 21 from entering` the lower open end of the tube. Such formation of the stem portion 12 also prevents lateral shifting of the firing portion 14 with respect to the sparking point 15. It will also beobserved a space exists between the head 16 and the sleeve 18 at all times, sothat the priming fluid upon being poured into the upper concave surface of the cap 17, may readily pass into the passageway 20.

lVhen it is desired to prime a cylinder of an engine with which the spark plug is used, the cap 17 may be rotated in a right hand direction and which action through the threaded sleeve 18 will feed the central electrode 25 downwardly into a position as illus- .trated in Figure 3, thus opening the lower end of the passageway 20 through the tube 7. The gasoline or other priming fluid may then be poured into the concaved upper face of the cap 17 whence it will flow through the passageway 20 and around the firing point 14. After a sufficient amount of the priming fluid has been poured through the plug, the cap 17 may be rotated in a left hand direction and which action` through the pin 19 will raise the valve 13 to a closed position upon the valve seat 9 and thus close the passageway 20.

From the foregoing description it will be apparent'that an extremely simple and etlicient priming plug for use in connection with internal combustion engines has been provided, embodying a central electrode shiftable longitudinally through the spark plug for the opening and closing of a passageway extending through the spark plug.

Various minor changes may be made to the specific form of invention herein shown and described, without departing from the spirit of the invention or the scope of the following claims.

v I claim;

1. In a spark plug, the combination of an insulating eorerprovided with a central bore,

a metal sleeve fitting in the bore and having an externally threaded end portion projecting past the outer end of the core, a central electrode extending through the sleeve and iaving an intermediate flattened stem portion of greater length than the sleeve for forming a passageway' through the sleeve, and having an enlarged portion at its inner end lof greater diameter than the sleeve and forming a valve head for seating engagement with the inner end of the sleeve, a cap threaded upon the outer end of the sleeve, and means rigidly connecting the cap to the outer end of the electrode whereby the electrode will be rotated and moved longitudinally within the sleeve upon rotation of the cap.

2. In a spark plug, the combination of an insulating core provided with a central bore, a sleeve extending through the bore and having` an externally threaded end portion projecting past the outer end of said core, a central electrode embodying a flattenedv stem portion, extending through the sleeve and having an enlarged portion at the inner end of its stem forming a valve for seating against the inner end of the sleeve and having the opposite end of the flattened stem portion projecting past the outer end of the sleeve, means for securing the sleeve in the bore of the insulating core, a cap having a threaded bore into which a portion of the flattened stem portion projects, threaded upon the outer end of the sleeve and having a concaved upper surface sloping toward .said threaded bore, and a pin connecting the cap to the stem portion of the electrode at a point outwardly of the outer end of the sleeve.

In a spark plug, the combination of an insulating core provided with a central bore. a sleeve fitting in said bore having a seat at its inner end and having an externally threaded portion extending past the outer end of said core, a central electrode extending tl'irough said sleeve embodying an intermediate. semi-circular shaped stem portion having an enlarged valve head formed at its inner end for Seating against the inner end of said sleeve and having its outer end extending past the outer end of the sleeve and provided with a head of a diameter no greater than the internal diameter of said sleeve, a cap threaded upon the outer end of the sleeve, and means connecting the cap to the outwardly projecting end of the electrode for seating and unseating of the valve head upon rotation of said cap.

4. In a spark plug, the combination of an insulating core provided with a central bore, a sleeve extending through the bore and having an externally screw threaded outer end, a central electrode extending through the sleeve having an enlarged portion at its inner end forming a valve head for seating against the inner end of the sleeve, an intermediatey semi-circular shaped stem` portion extending trom a point close adjacent said valve head toa point past the outer end of and being of greater length than the sleeve, capthreaded uponthe outer end of the sleeve having a concavedl upper surface for directinor a fluid laced in the ca to said z: p P passageway, and means rigidly connecting i Vthe cap to the outer end of the electrode for imparting longitudinal shifting movement v yto the electrode upon rotation of the cap.

. 5. In a spark plug, the combination of an I insulating core provided with a central bore,

a sleeveiextending thru the bore and having an externallyy threaded end portion projecting past the 'outer end of said core, a central ,electrode fittmg 1n said sleeve embodying a flattened lstem portion of greater length than said sleeve having a Valve formed at its innerend and a head provided at lits outer end normally disposed voutwardly ol? the "louter end of the sleeve, a priming cap havingga threadedl bore for threaded connection With the threaded projection of said K sleeve, said threaded bore to receive the head and aportion of the flattened stem portion of the electrode, and a pi-n connecting the cap and electrode, said pin extending transversely through the threaded bore of the cap and through the electrode at a point directly beneath its head.

6. ln a spark plug, the combination of an insulating core provided with a central bore, af sleeve Vfitting in the bore and having an externally threaded portion projecting past the outer end of the core, a central electrode provided with a flattened stem portion, eX- tending through the sleeve and having a valve head formed at its inner end for seating engagement with the inner end of the sleeve, and means vfor moving the electrode longitudinally Within the sleeve for seating and unseating of the valve head for opening and closing of a passageway through the sleeve, comprising a cap of insulating material provided with an axial bore, an intern ally threaded metallic Sleeve fitting in said bore for threaded engagement with the threaded end of said sleeve, and a pin extending transversely through the cap and sleeve and-the outer portion of the electrode for securing of the sleeve Within the. cap and the cap to the electrode.

JOHN M. BRINGMAN. 

